Some cargo trailers, such as some agricultural trailers, have conveyors for conveying cargo. These conveyors are often driven by a chain placed in tension by a rotating sprocket. Pintle chains are often desirable in agricultural applications because the open barrels of each pinned connection of the pintle chain provides for improved and/or simplified cleaning. Open barrel chains, such as pintle chains, in drive-train applications are known to have been driven by conventional sprockets. These conventional sprockets have had more than twelve teeth, and have been driven in rotation by hydraulic drives, at least in some instances. The torque required to drive a sprocket in rotation is approximately equal to the product of a diameter of the sprocket with a tension in the chain.
The ability to convey heavy loads has been and continues to be desirable. To accommodate increased loads while using conventional hydraulic drives and existing pintle chains, some have attempted to reduce the necessary drive-torque corresponding to the increased loads by reducing the sprocket diameter and the number of teeth to seven teeth. However, this approach has resulted in a significant reduction in chain life and chain reliability.